If you have a stand-alone video card that is installed on an AGP or PCI Express slot then yes, it is compatible with The Sims 3. But if you have an integrated/built-in video card the Bare Minimum CPU requirement is raised to an Intel Pentium Dual Core 2.00 GHz (or Intel Core2Duo e6300 1.8GHz).
I also need to know how much RAM is on your computer.
If you do not know what video card you have or how much system RAM is on your computer that is not a problem. I just created a tutorial that will show you how to easily look that up with 20 seconds. Checkout the video tutorial at the end of the article to learn how..
http://www.cleartechinfo.com/How-To-Find-Computer-Hardware-Operating-System-Specifications-Windows-7NOTE: Even though this is done in Windows 7 everything still applies. I learned how to lookup system specs using this method on my Vista computer.